---
id: CVE-2026-112951
title: >-
  ApostropheCMS: Color field validation bypass allows stored XSS via HTML
  appended after rgb()/hsl() prefix
summary: >-
  ApostropheCMS is an open-source Node.js content management system. Prior to
  4.34.0, the color field accepts trailing content after a valid rgb() or hsl()
  prefix because its TinyColor validation does not require the entire value to
  match …
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-79
vendor: apostrophecms
product: apostrophe
affected:
  - apostrophe < 4.34.0
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-20T16:42:47.280895Z'
exploitAvailable: true
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T16:43:32.126Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-112951'
references:
  - url: >-
      https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-vmgj-9cwm-cf3h
    label: >-
      https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-vmgj-9cwm-cf3h
  - url: >-
      https://github.com/apostrophecms/apostrophe/commit/06e4b377f3c360f9e89c32dccd7e505ad5ddf498
    label: >-
      https://github.com/apostrophecms/apostrophe/commit/06e4b377f3c360f9e89c32dccd7e505ad5ddf498
  - url: >-
      https://github.com/apostrophecms/apostrophe/commit/40b989b1a9dd23d30029b8ce7668634265cfe5ea
    label: >-
      https://github.com/apostrophecms/apostrophe/commit/40b989b1a9dd23d30029b8ce7668634265cfe5ea
  - url: 'https://github.com/apostrophecms/apostrophe/releases/tag/apostrophe@4.34.0'
    label: 'https://github.com/apostrophecms/apostrophe/releases/tag/apostrophe@4.34.0'
tags:
  - cve.org
  - exploit-available
ingestedAt: '2026-10-20T16:10:53.309Z'
---

## Overview

ApostropheCMS is an open-source Node.js content management system. Prior to 4.34.0, the color field accepts trailing content after a valid rgb() or hsl() prefix because its TinyColor validation does not require the entire value to match a color. An authenticated user with edit rights can store arbitrary HTML after a valid color prefix. When the stored value is rendered, the payload executes, resulting in stored XSS. This issue is fixed in version 4.34.0.

## Affected

- `apostrophe < 4.34.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.